What happened
On 8 July 1999, a Piper PA-28-161, registration G-BSVF, was involved in a ground collision at Wycombe Air Park, Buckinghamshire. The aircraft was being operated on a private flight and was taxiing from a refuelling pump toward the apron. The intended route required the pilot to navigate past a row of parked aircraft, performing a 180-degree right turn to pass behind the first row and in front of a second row.
While executing the right turn, the pilot experienced what felt like a "spongy" sensation in the left brake toe-pedal. Consequently, the aircraft drifted left of the yellow taxiway centreline, resulting in the left wingtip of the Piper PA-28-161 striking the nose of a parked Cessna 172. The collision caused a dent to the wingtip of G-BSVF and a dent to the engine cowling of the stationary Cessna 172. There were no injuries to the pilot. Following the impact, the pilot engaged the parking brake, notified Air Traffic Control, and shut down the engine.
The investigation
The investigation examined the mechanical state of the braking system and the pilot's actions. Maintenance checks performed by the aircraft's maintenance organisation following the event determined that the parking brake was sufficiently efficient to hold the aircraft when pushed. Furthermore, subsequent taxiing tests under power demonstrated that both the nosewheel steering and the braking systems were functioning without fault.
Discrepancies in the assessment of the taxi speed were also noted. While eyewitnesses suggested the aircraft was travelling at an excessive speed, the pilot maintained that the throttle was at idle during the turn and argued that the minor nature of the damage was inconsistent with high-speed impact.